Are there spinning rules?

Are there? By rules, I mean things that must be done (or should never, ever be done). I have thought about this a lot. One example? Well, I don't  believe in weighting yarn intended for knitting while they dry. Setting the twist doesn't require weights and that fiber, once wet is likely to bias and might ruin someone's garment. So, for me, it's a rule; I never put a weight on my yarns while they dry....if they have too much twist, I either run the yarn back through on my e-spinner or I set it aside for weaving.

I'd love some thoughts from others. Does anything go? Are there rules?